Backhoe

ABSTRACT

A backhoe includes a boom with one end rotatably supported by a supporting structure fixed on a working vehicle, and a boom cylinder with one end rotatably supported by the supporting structure, and with another end rotatably supported by the boom, the boom cylinder that drives the boom by operating in a freely retractable manner. The boom cylinder includes a piston, a cylinder tube that contains the piston, a piston rod connected to the piston, a scale rod fixed in parallel to the piston rod and operates along the outer surface of the cylinder tube in response to an operation of the piston rod, a scale arranged on the outer surface of the cylinder tube along the scale rod, and an indicator provided on the piston rod and operates along the scale in response to the operation of the piston rod.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a backhoe.

2. Description of the Related Art

Conventionally, there have been known working vehicles such as a construction equipment vehicle and an agricultural equipment vehicle, each of which includes a backhoe. For example, tractors that include the backhoe in the rear portion of the vehicle body thereof have been known (see Patent Literature 1). Then, during an excavating operation, the backhoe carries out excavation in such a manner as to dig in the ground to a predetermined depth. In this case, after the backhoe excavates the ground to an appropriate depth, an operator needs to get out of a tractor and measure the depth, and when the backhoe fails to dig in the ground to the predetermined depth, the operator needs to repeat the excavating operation by use of the backhoe.

CITATION LIST Patent Literature

PTL 1: Japanese Unexamined Patent Application Publication No. 2010-71054

BRIEF SUMMARY OF THE INVENTION Problems to be Solved by the Invention

However, during the above-mentioned operation, the operator needs to stop the excavating operation, get out of the tractor, and measure the depth of the excavation, so that there is a problem in that working efficiency is deteriorated, and the operation is time-consuming.

It is an object of the present invention to provide a backhoe that can measure the depth of excavation in a state where an operator rides on a working vehicle.

Means of Solving the Problems

A backhoe of the present invention may include a boom with one end configured to be rotatably supported by a working vehicle or a supporting structure fixed on the working vehicle, and a boom cylinder with one end configured to be rotatably supported by the working vehicle or the supporting structure, and with another end configured to be rotatably supported by the boom, the boom cylinder configured to drive the boom by operating in a freely retractable manner, and the boom cylinder includes a piston, a cylinder tube configured to contain the piston, a piston rod configured to be connected to the piston, a scale rod configured to be fixed in parallel to the piston rod and configured to operate along an outer surface of the cylinder tube in response to an operation of the piston rod, a scale configured to be arranged on the outer surface of the cylinder tube along the scale rod, and an indicator configured to be provided on the scale rod and configured to operate along the scale in response to the operation of the piston rod.

For example, the backhoe described above is configured to include an arm with one end configured to be rotatably supported by the boom, an arm cylinder with one end configured to be rotatably supported by the boom, and with another end configured to be rotatably supported by the arm, the arm cylinder configured to drive the arm by operating in a freely retractable manner, a bucket with one end configured to be rotatably supported by the arm, and a bucket cylinder with one end configured to be rotatably supported by the arm and with another end configured to be rotatably supported by the bucket, the bucket cylinder configured to drive the bucket by operating in a freely retractable manner.

Advantageous Effects

According to one aspect of the backhoe of the present invention, the scale rod, the scale, and the indicator are provided in the boom cylinder, so that an operator can read the values of the scale indicated by the indicator while sitting on a driving seat. That is, the depths of the excavation can be measured in a state where the operator rides on the working vehicle.

Also, according to another aspect of the backhoe of the present invention, the arm and the bucket are provided, and the arm and the bucket are arranged in the vertical direction at the place excavated below, and the tip end of the bucket is operated in such a manner as to come in contact with the bottom surface of a section excavated, so that the depths of the excavation can be measured.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a side view of a tractor.

FIG. 2 is a perspective view of a boom cylinder.

FIG. 3 is a view illustrating an example of measuring the depth of excavation prior to the excavation.

FIG. 4 is an enlarged view of the boom cylinder in a state of FIG. 3.

FIG. 5 is a view illustrating an example of measuring the depth of the excavation.

FIG. 6 is an enlarged view of the boom cylinder in a state of FIG. 5.

FIG. 7 is a view illustrating the retracted state of the backhoe during travel.

FIG. 8 is an enlarged view of the boom cylinder in a state of FIG. 7.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A backhoe described below can be applied to all working vehicles. Hereinafter, a tractor will be described as a typified working vehicle.

First, a tractor 100 will be briefly described.

FIG. 1 is a side view of the tractor 100. It is noted that the back-and-front direction and the up-and-down direction of the tractor 100 are represented in the diagram.

The tractor 100 is mainly constituted by a frame 1, an engine 2, a transmission 3, a front axle 4, and a rear axle 5. Also, the tractor 100 includes a backhoe 6.

The frame 1 serves as a framework of the tractor 100. The engine 2 described below is mounted on the frame 1.

The engine 2 converts energy obtained by combusting fuel into a rotary motion. When an operator operates an accelerator lever, the engine 2 changes a driving state in response to the operation. Also, the engine 2 keeps a constant rotational speed even when loads are varied.

The transmission 3 switches the forward and backward movements of the tractor 100 and shifts gears. When the operator operates a shift lever, the transmission 3 changes operational states in response to the operation. The transmission 3 includes a stepless variable transmission (HMI or I-HMT) of a hydraulic-and-mechanical type as a gearbox.

The front axle 4 transmits the rotary power of the engine 2 to front tires 41. The rotary power of the engine 2 is inputted to the front axle 4 via the transmission 3. It is noted that a steering gear is disposed in parallel to the front axle 4. When the operator operates a handle, the steering gear changes the steering angle of the front tires 41 in response to the operation.

The rear axle 5 transmits the rotary power of the engine 2 to rear tires 51. The rotary power of the engine 2 is inputted to the rear axle 5 via the transmission 3. It is noted that a PTO output mechanism is provided in the rear axle 5. When a rotary cultivator is mounted in place of the backhoe 6, the PTO output mechanism inputs the rotary power to the rotary cultivator.

The backhoe 6 is used for carrying out the operation of excavating earth and sand. Hydraulic oil is supplied to the backhoe 6 via an oil hydraulic circuit not illustrated. The backhoe 6 is coupled with the frame 1 by means of a supporting structure 7. The supporting structure 7 includes a boom bracket 71 that supports a boom 61 described later, and the supporting structure 7 is constituted by a plurality of plate members parallel to the back-and-front direction and the up-and-down direction. Then, the front end portion of the supporting structure 7 is fixed on the frame 1, and the rear end portion of the supporting structure 7 is fixed on the backhoe 6. It may be such that the supporting structure 7 is eliminated, and the backhoe 6 is configured to be directly coupled with the frame 1.

An outrigger 8, which allows the backhoe 6 to connect to the ground during use and prevents the backhoe 6 from falling, is provided on both right and left sides of the supporting structure 7. Also, when the backhoe 6 is used, a driving seat 9 oriented to the front is rotated at 180 degrees in the horizontal direction and placed in a state of being oriented to the rear. Also, a fixed seat may be provided for operating the backhoe 6.

The backhoe 6 includes the boom 61, an arm 62, a bucket 63, a boom cylinder 64, an arm cylinder 65, and a bucket cylinder 66.

One end of the boom 61 is rotatably supported by the boom bracket 71, and the other end of the boom 61 rotatably supports the arm 62. One end of the arm 62 is rotatably supported by the boom 61, and the other end of the arm 62 rotatably supports the bucket 63. One end of the bucket 63 is rotatably supported by the arm 62.

One end of the boom cylinder 64 is rotatably supported by the boom bracket 71, and the other end of the boom cylinder 64 is rotatably supported by the boom 61, and the boom cylinder 64 operates in a freely retractable manner, thereby driving the boom 61 in such a manner as to rotate. One end of the arm cylinder 65 is rotatably supported by the boom 61, and the other end of the arm cylinder 65 is rotatably supported by the arm 62, and the arm cylinder 65 operates in a freely retractable manner, thereby driving the arm 62 in such a manner as to rotate. One end of the bucket cylinder 66 is rotatably supported by the arm 62, and the other end of the bucket cylinder 66 is rotatably supported by the bucket 63, and the bucket cylinder 66 operates in a freely retractable manner, thereby driving the bucket 63 in such a manner as to rotate.

Next, the structure regarding the measurement of the depth of excavation and the method of measuring the depth of the excavation will be described.

FIG. 2 is a perspective view of the boom cylinder 64. The boom cylinder 64 includes a piston (not illustrated), a cylinder tube 641, a piston rod 642, a scale rod 643, a scale 644, and an indicator 645.

The cylinder tube 641 is a cylindrical member that contains the piston that slidably reciprocates, and one end of the cylinder tube 641 is sealed by a cylinder head 646, and the other end of the cylinder tube 641 is sealed by a cylinder bottom 647. A through hole, through which the piston rod 642 penetrates, is formed in the center of the cylinder head 646. A shaft hole 648, which is penetrated in the vertical direction with respect to the longitudinal direction of the piston rod 642, is formed in the cylinder bottom 647. The shaft hole 648 is a hole through which a bolt or the like penetrates, which allows the boom cylinder 64 and the boom 61 to be coupled with each other. The hydraulic oil is supplied to the cylinder tube 641 via, the oil hydraulic circuit (not illustrated).

The piston rod 642 penetrates the through hole of the cylinder head 646 in a movable manner. The piston is connected to one end of the piston rod 642, and a shaft hole 649, which is penetrated in the vertical direction with respect to the longitudinal direction of the piston rod 642, is formed at the other end of the piston rod 642. The shaft hole 649 is a hole through which a bolt or the like penetrates, which allows the boom cylinder 64 and the boom bracket 71 to be coupled with each other.

The scale rod 643 is a rod-shaped member having an approximately same length as that of the cylinder tube 641. A metal plate member 64 a that is bent and curved is fixed with a bolt or a pin at one end of the scale rod 643. Then, the metal plate member 64 a is fixed with a bolt through the shaft hole 649, which is the other end of the piston rod 642, in such a manner that the scale rod 643 and the piston rod 642 are disposed in parallel. Also, the scale rod 643 penetrates a through hole 64 b provided in the scale 644 in a movable manner.

The scale rod 643 operates along the scale 644 in response to the operation of the piston rod 642. in other words, the scale rod 643 linearly operates along the longitudinal direction on the outer surface of the cylinder tube 641.

The scale 644 is a member or a section on which the depths of excavation are represented. As illustrated in FIG. 2, for example, the scale 644 is such that a metal plate is bent in a C-shape, and a protruding portion 64 c is formed by cutting and raising part of the metal plate, and an elongated hole 64 d is formed in the protruding portion 64 c, and a member inclusive of the through hole 64 b is welded. Numerical values (whose unit is represented as feet) that represent the depths of the excavation, and a symbol T that represents the position of the backhoe 6 retracted during the travel are illustrated on the surface of the scale 644.

The scale 644 is arranged on the outer surface of the cylinder tube 641 along the scale rod 643 and fixed on the cylinder tube 641 by means of two metal clamping bands 64 e. More specifically, the scale 644 is arranged on a surface of the cylinder tube 641 on the side of the driving seat 9 (surface on the side opposite to the side of the boom 61), so that the numerical values that represent the depths of the excavation can be visible for the operator who sits on the driving seat 9.

The mode of the scale 644 is not limited in a specific manner as long as the depths of the excavation can be represented on the outer surface of the cylinder tube 641. For example, a mode may be applied wherein the depths of the excavation are directly painted or inscribed on the cylinder tube 641, and the cylinder tube 641 is used as the scale 644. Also, a cutting sheet on which the depths of the excavation are printed may be pasted on the cylinder tube 641.

The indicator 645 is a doughnut-shaped member provided at the other end of the scale rod 643 and fixed in a state of being penetrated by the scale rod 643. It is preferable that the indicator 645 be painted in recognizable colors such as red, in order to indicate the reading position regarding the depths of the excavation, which are represented on the scale 644. It is noted that the shape of the indicator 645 is not limited as long as the indicator 645 can indicate the reading position regarding the depths of the excavation. For example, a mark that is colored. in red and attached in the vicinity of the other end of the scale rod 643 may be applied.

The indicator 645 is integrated with the scale rod 643, so that the indicator 645 operates as the scale rod 643 does. That is, the indicator 645 linearly operates along the scale 644 in response to the operation of the piston rod 642.

The protruding portion of the scale 644 is provided along the scale rod 643, and the elongated hole 64 d is formed opposite to the scale rod 643. A protruding portion protruded from the indicator 645 penetrates the elongated hole 64 d in a movable manner, and a wing nut 64 f is threadedly engaged with the protruding portion in order to prevent the protruding portion from coming off from the elongated hole 64 d. The protruding portion 64 c is guided by the elongated hole 64 d during the operation of the indicator 645, so that the operation of the indicator 645 can be stabilized.

The value of the scale 644, regarding the depths of the excavation that are indicated by the indicator 645, is provided based on a criterion in a case where the tractor 100 is horizontally positioned, and the arm 62 and the bucket 63 are arranged in the vertical direction, and the tip end of the bucket 63 is brought into contact with the bottom surface of a section excavated. In this case, the value of the indicator 645 indicates the length in the vertical direction from the ground plane of the tractor 100 (ground plane of the front tires 41, the rear tires 51, the outrigger 8, and the like) to the tip end of bucket 63 (see FIGS. 3 and 5).

FIG. 3 is a view illustrating an example of measuring the depth of excavation prior to the excavation. FIG. 4 is an enlarged view of the boom cylinder 64 in a state of FIG. 3.

As illustrated in FIG. 3, on the flat ground prior to the excavation, the outrigger 8 is grounded, and the arm 62 and the bucket 63 are arranged in the vertical direction, and the tip end of the bucket 63 comes in contact with the same surface as the ground plane A of the outrigger 8. In this time, as illustrated in FIG. 4, the indicator 645 indicates the position of “0”. This represents that the depth of the excavation is 0 feet.

In the state of FIG. 3, the scale 644 and the indicator 645 face the driving seat 9 oriented backward, so that the operator can read the value of the scale 644 that is indicated by the indicator 645 while sitting on the driving scat 9.

FIG. 5 is a view illustrating an example of measuring the depth of the excavation. FIG. 6 is an enlarged view of the boom cylinder 64 in a state of FIG. 5.

As illustrated in FIG. 5, the outrigger 8 is grounded, and the arm 62 and the bucket 63 are arranged in the vertical direction at a place excavated below, and the tip end of the bucket 63 comes in contact with the bottom surface B of the section excavated. In this time, as illustrated in FIG. 6, the indicator 645 indicates the position of about 5.6. This represents that the depth D of the excavation is about 5.6 feet.

In the state of FIG. 5, the scale 644 and the indicator 645 are positioned obliquely downward with respect to the driving seat 9 oriented backward, so that the operator can read the value of the scale 644 that is indicated by the indicator 645 while sitting on the driving seat 9.

FIG. 7 is a view illustrating the retracted state of the backhoe 6 during travel. FIG. 8 is an enlarged view of the boom cylinder 64 in a state of FIG. 7.

As illustrated in FIG. 7, the boom 61 is raised uppermost, and the arm 62 is folded obliquely downward, and the bucket 63 is folded between the boom 61 and the arm 62, which represents a state where the backhoe 6 is retracted. Also, the outrigger 8 is raised and retracted. In this time, as illustrated in FIG. 8, the indicator 645 indicates the position of T. This represents that the backhoe 6 is at a retracted position.

In the state of FIG. 7, the scale 644 and the indicator 645 face the driving seat 9 oriented backward, so that the operator can read the value of the scale 644 that is indicated by the indicator 645 while sitting on the driving seat 9.

It is noted that the mechanical constitution is used as the constitution of measuring the depths of the excavation in the present embodiment described above, but electrical constitution may be applied in place of the mechanical constitution. For example, a sensor that detects the degrees of extension and contraction of the boom cylinder 64, a calculating portion that calculates the depth of the excavation based on the degrees of the extension and contraction, and a display portion that displays the calculated depth of the excavation can be used in place of the scale rod 643, the scale 644, and the indicator 645. 

What is claimed is:
 1. A backhoe comprising: a boom with one end configured to be rotatably supported by a supporting structure fixed on a working vehicle; and a boom cylinder with one end configured to be rotatably supported by the supporting structure, and with another end configured to be rotatably supported by the boom, the boom cylinder configured to drive the boom by operating in a freely retractable manner, wherein the boom cylinder includes: a piston; a cylinder tube configured to contain the piston; a piston rod configured to be connected to the piston; a scale rod configured to be fixed in parallel to the piston rod and configured to operate along an outer surface of the cylinder tube in response to an operation of the piston rod; a scale configured to be arranged on the outer surface of the cylinder tube along the scale rod; and an indicator configured to be provided on the scale rod and configured to operate along the scale in response to the operation of the piston rod.
 2. The backhoe according to claim 1, further comprising an arm with one end configured to be rotatably supported by the boom; an arm cylinder with one end configured to be rotatably supported by the boom, and with another end configured to be rotatably supported by the arm, the arm cylinder configured to drive the arm by operating in a freely retractable manner; a bucket with one end configured to be rotatably supported by the arm; and a bucket cylinder with one end configured to be rotatably supported by the arm and with another end configured to be rotatably supported by the bucket, the bucket cylinder configured to drive the bucket by operating in a freely retractable manner. 